Xperia Arc SD card problem

Am facing a big issue now.this morning the phone got stuck suddenly and could not do nothing. even pressing the power button did not help. so i had to remove battery manually and restart the phone. since then the phone is not reading the memory card and says unmounted. tried removing it and inserted it many times and it is still not getting detected. have so many things in the card. tried the card in another phone and a card reader and it is still not getting detected. an adnroid app was being updtaed and after this the Android Booster app was scanning it as usual. it is during this scan that the phone hung up and was frozen. any suggestions? i have everything in the card and i need it to work or atlease retreive the data. the issue is the card is not being detected by any device...........help please.............